Thousands of feds have one thing in common - they perform work most people don't associate with the government. In our ongoing series, Cool Jobs in Government, Federal News Radio uncovers and highlights some of the most interesting and unorthodox ways feds spend their days.

Khalid Hussain manages the center and says the place is "friendly" for stamps because it's under the ground in caves that are about 270 million years old.

"There is approximately 5 million square feet of underground space here in this facility, and . . . close to 1,500 employees work in this complex. . . . We are three-quarters of a mile inside, as you come into the entrance, and we are 150 feet underground. The temperature remains 72 degrees."

There are some humidity controlled areas for certain stamps, but, for the most part Hussain says they really don't have to expend much energy because the conditions in the cave are so pleasant.

There are about $400 - 600 million (yes, million) worth of stamps stored in the facility at any given time.

He says they have customers from all over the world who buy stamps for their collections directly from the cave.

Since some of the stamps are very valuable, there is a lot of security in and around the cave.

"The security is there -- both in a physical presence and there is also an electronic presence. This is a very secure place."

As far as working in the cave, Hussain says it has its advantages and disadvantages, "There are days [when it is] 105 degrees outside, and it's wonderful [in the cave]. Same in the winter time."

As for what he likes best about the job, Hussain says it's the philators themselves.

"I love what I'm doing and stamps . . . really reflect the greatness of our nation in a miniature art form. Stamp collection is one of the coolest hobbies in the world. People who collect stamps are very unique and distinct, and very patriotic people. So, dealing with them and how they appreciate the aesthetic of the stamp . . . that's amazing."